1 files changed, 124 insertions, 4 deletions

diff --git a/gui/internal/ui/plan.go b/gui/internal/ui/plan.go
index f6f2952..97d8599 100644
--- a/gui/internal/ui/plan.go
+++ b/gui/internal/ui/plan.go
@@ -5,6 +5,8 @@ package ui
 import (
 	"context"
 	"fmt"
+	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/diamondburned/gotk4/pkg/gdk/v4"
@@ -35,8 +37,18 @@ type planView struct {
 
 	list    *gtk.ListBox
 	details *gtk.TextView
-	menu    *gtk.Popover
-	menuRow int
+
+	previewNote   *gtk.Label
+	picture       *gtk.Picture
+	pictureFrame  *gtk.ScrolledWindow
+	previewText   *gtk.TextView
+	previewScroll *gtk.ScrolledWindow
+	previewTmp    string
+	previewFor    string
+	previewOff    bool
+	startSelected bool
+	menu          *gtk.Popover
+	menuRow       int
 
 	tab      *model.PlanTab
 	cancelOp context.CancelFunc
@@ -102,13 +114,53 @@ func newPlanView(w *Window) *planView {
 	p.details.SetBottomMargin(6)
 	detailScroll := gtk.NewScrolledWindow()
 	detailScroll.SetChild(p.details)
-	detailScroll.SetSizeRequest(320, -1)
+	detailScroll.SetVExpand(true)
+	detailScroll.SetSizeRequest(-1, 160)
+
+	// Under the explanation, a look at the file itself: a picture for an
+	// image, the first page for a PDF, the first lines for anything that is
+	// text (his request, 2026-09-16).
+	p.previewNote = gtk.NewLabel("")
+	p.previewNote.SetXAlign(0)
+	p.previewNote.SetMarginStart(8)
+	p.previewNote.SetMarginEnd(8)
+	p.previewNote.SetEllipsize(pango.EllipsizeEnd)
+	p.previewNote.SetMaxWidthChars(20)
+	p.previewNote.AddCSSClass("dim-label")
+	p.picture = gtk.NewPicture()
+	p.picture.SetCanShrink(true)
+	p.picture.SetContentFit(gtk.ContentFitContain)
+	p.picture.SetVisible(false)
+	pictureFrame := gtk.NewScrolledWindow()
+	pictureFrame.SetChild(p.picture)
+	pictureFrame.SetSizeRequest(-1, 280)
+	pictureFrame.SetVisible(false)
+	p.pictureFrame = pictureFrame
+	p.previewText = gtk.NewTextView()
+	p.previewText.SetEditable(false)
+	p.previewText.SetMonospace(true)
+	p.previewText.SetLeftMargin(8)
+	p.previewText.SetRightMargin(8)
+	p.previewText.SetTopMargin(6)
+	previewScroll := gtk.NewScrolledWindow()
+	previewScroll.SetChild(p.previewText)
+	previewScroll.SetSizeRequest(-1, 260)
+	previewScroll.SetVisible(false)
+	p.previewScroll = previewScroll
+
+	detailBox := gtk.NewBox(gtk.OrientationVertical, 0)
+	detailBox.Append(detailScroll)
+	detailBox.Append(gtk.NewSeparator(gtk.OrientationHorizontal))
+	detailBox.Append(p.previewNote)
+	detailBox.Append(pictureFrame)
+	detailBox.Append(previewScroll)
+	detailBox.SetSizeRequest(340, -1)
 
 	// A pane the user can drag: on a narrow window the list needs the room,
 	// on a wide one the explanation does.
 	panes := gtk.NewPaned(gtk.OrientationHorizontal)
 	panes.SetStartChild(listScroll)
-	panes.SetEndChild(detailScroll)
+	panes.SetEndChild(detailBox)
 	panes.SetResizeStartChild(true)
 	panes.SetResizeEndChild(false)
 	panes.SetShrinkEndChild(false)
@@ -272,6 +324,9 @@ func (p *planView) onScan() {
 			return
 		}
 		p.tab = tab
+		if !p.startSelected {
+			tab.SelectNone()
+		}
 		p.fillList()
 		c := tab.Counts
 		p.w.setStatus("%d scanned, %d to act on, %d excluded, %d skipped, %d with warnings",
@@ -479,4 +534,69 @@ func (p *planView) showDetails(i int) {
 		b.WriteString("\n" + escape(r.Outcome) + "\n")
 	}
 	p.details.Buffer().SetText(b.String())
+	p.showPreview(r.Rel)
+}
+
+// showPreview looks at the file behind row rel, off the main loop: reading
+// it, and rendering a PDF page, takes long enough to stutter the window.
+func (p *planView) showPreview(rel string) {
+	if p.tab == nil || p.previewOff {
+		return
+	}
+	path := filepath.Join(p.tab.Dir.Root, filepath.FromSlash(rel))
+	if p.previewFor == path {
+		return
+	}
+	p.previewFor = path
+	p.pictureFrame.SetVisible(false)
+	p.previewScroll.SetVisible(false)
+	p.previewNote.SetText("looking at " + escape(rel) + "...")
+	if p.previewTmp == "" {
+		dir, err := os.MkdirTemp("", "krino-preview-")
+		if err != nil {
+			p.previewNote.SetText(escape(err.Error()))
+			return
+		}
+		p.previewTmp = dir
+	}
+	var pv model.Preview
+	runInBackground(func(ctx context.Context) error {
+		pv = model.MakePreview(ctx, path, p.previewTmp)
+		return nil
+	}, func(error) {
+		if p.previewFor != path {
+			return // another row was chosen while this one was read
+		}
+		p.previewNote.SetText(escape(pv.Note))
+		switch pv.Kind {
+		case model.PreviewImage:
+			p.picture.SetFilename(pv.Image)
+			p.picture.SetVisible(true)
+			p.pictureFrame.SetVisible(true)
+		case model.PreviewText:
+			p.previewText.Buffer().SetText(escapeText(pv.Text))
+			p.previewScroll.SetVisible(true)
+		}
+	})
+}
+
+// applyPrefs turns the file preview on or off, and says how a fresh plan
+// starts.
+func (p *planView) applyPrefs(prefs model.Prefs) {
+	p.previewOff = !prefs.Preview
+	p.startSelected = prefs.SelectAll
+	if p.previewOff {
+		p.previewFor = ""
+		p.pictureFrame.SetVisible(false)
+		p.previewScroll.SetVisible(false)
+		p.previewNote.SetText("")
+	}
+}
+
+// closePreview removes what the previews left behind.
+func (p *planView) closePreview() {
+	if p.previewTmp != "" {
+		os.RemoveAll(p.previewTmp)
+		p.previewTmp = ""
+	}
 }